Ashino Onsen is located amid the rich natural surroundings of Nasu and is a modern therapeutic bath resort said to be so effective that it is known as the "canes-forget bath." Its private hot spring source, with an astonishing pH of 9.9, has a famously slippery, silky feel, as if bathing in lotion, and is offered as 100% free-flowing spring water with no added water. Its signature medicinal herb bath features a rich extract of carefully blended herbal ingredients, creating a pleasantly stimulating experience that envelops the whole body. The sauna is a mint-scented medicinal herb mist sauna, where the mild temperature gently moistens the nose and throat and leads you into deep relaxation. The outdoor area also includes a crisp, refreshing cold plunge bath. It is a supreme retreat where the power of genuine hot springs, the healing force of herbs that stimulate all five senses, and the sauna come together to soothe both body and mind at the deepest level.